99mTc-PPM应用于肺肿瘤的显像和导向手术的研究

背景与目的:肉眼判断和冰冻切片病理检查是我们在术中判断肿瘤的良恶性及其侵袭范围的常规方法,但肉眼判断缺乏准确性,术中冰冻检查需要等待一段时间;而术中用手持式γ探测仪( gamma detecting probe, GDP)判断肿瘤的浸润范围及转移程度,可以帮助术者快速准确地决定手术切除范围及治疗方案,使手术更加合理化及个体化.本研究以 99mTc 培普利欧霉素( peplomycin,PPM)为肿瘤示踪剂,进行肺癌显像和放射性核素导向手术的初步临床研究.方法:对 37例肺肿瘤患者注射 99mTc PPM,术前进行肺肿瘤的显像,以 ROI(region of interest)法处理并计算 T/NT;术中以手持式γ探测仪 (GDP)对手术标本进行放射性探测,以正常肺组织为本底组织( NT)计算 T/NT比值,以比值的高低来确定探测标本的性质.结果:良、恶性肿瘤对 99mTc PPM的摄取值 (良性病变 N/NT 1.04± 0.08,肺癌 N/NT 1.41±0.16)的差异有统计学意义( P< 0.01) ;以良性病变 T/NT的 x± 2s为判断良恶性病变的阈值, 99mTc PPM显像对肺癌诊断灵敏度为 90%,特异性为 87.5%,准确度为 89.3%;应用 GDP能够准确地探测出肿瘤的侵袭范围,并可以判定肿瘤的淋巴结转移情况,其灵敏度、特异性和准确率分别达到 91.0%、 88.0%和 90.0%.结论:可以将 99mTc PPM作为肿瘤示踪剂对肿瘤进行术前诊断和术中 GDP探测.术中应用 GDP探测,可以有效地判断肺癌的浸润范围及淋巴结转移,对肺癌手术的实施有一定的指导意义.

Clinical practice of 99mTc-peplimycin imaging and radio guided surgery for lung neoplasms

BACKGROUND & OBJECTIVE: Intraoperatively,the routine method to differentiate malignant lung neoplasms from benign lesions is by the judgment of naked eye or frozen section. It is not accurate to judge by naked eye and will take long time by frozen section. Using a gamma-detecting probe (GDP) to accurately detect the tumors and the metastases, the operators could decide the resection range and the treatment plan. This study was preliminary clinical practice of tumor imaging and radioimmunoguided surgery (RGS) using (99m)Tc-PPM (peplomycin) as a tumor tracer. METHODS: Thirty-seven patients were administered with injection of (99m)Tc-PPM. The images were taken preoperatively. Region of interest (ROI) method was performed and tumor-to- normal-tissue (T/NT) ratio was calculated on the image. The radioactivity of the specimens resected from the patients was detected using GDP at the time of surgery. T/NT ratio was obtained by comparing the radioactivity of the tumor tissue with the normal lung tissue. RESULTS: The uptake ratios (T/NT) of (99m)Tc-PPM were different between malignant and benign lesion (P< 0.01). The ratio (T/NT, x+/-2s) was regarded as the threshold for differentiation of malignant and benign lesions. The sensitivity, specificity, and accuracy of identifying malignant lesion were 90%, 87.5%, and 89.3%, respectively; GDP could be used to accurately detect the invasive range of the tumors, with the sensitivity, specificity, and accuracy of identifying lymph node metastases of 91%, 88%, and 90%, respectively. CONCLUSION: (99m)Tc-PPM is a useful agent in differentiating malignant lung neoplasm from benign lesions, and as a tumor tracer can be used in detecting tumor by GDP intraoperatively. The RGS is a simple method that can help the surgeon in the intraoperative assessment of the tumor and the lymph node metastases.